RLV12 and RL02 Tests

Today I picked up the long awaited RLV12 card (M8061) and a couple of RL02 disk packs which means I was able connect up and test the RL02 drives. I also got a RQDX3 MFM disk controller and an RD32 42MB disk, which I'll certainly be playing with later...

As with all new cards, first job was to check the RLV12's jumper settings against the manual. All were standard except for the vector address which was set to 460 instead of 160. Whoever set this up was kind enough to use a red wire, making the change obvious. Removing this and jumpering two neighbouring pins had the vector address back to 160. As all the cabling was already in place, it was simply a case of installing the module and connecting the BC80M cable from this to the first drive. The cable also has a ground strap which is connected to the chassis, using one of the threaded posts provided for this purpose.

BC80M cable and its ground strap connected to the RLV12 and system box.

As the boot ROM's memory map feature showed the controller was available at the expected address of 17774400, I booted a custom XXDP tape I'd made in advance as before. (If all went well, I was looking forward to being able to copy XXDP to an RL02 disk - what luxury!) The RLV12 manual lists the relevant tests as being the following, which should be executed in this order:

VRLB	RLV12 Diskless Diagnostic	Tests basic functionality of the controller such as registers, reset, interrupts and the maintenance function.
ZRLG	Controller Test Part 1	Exercises all functions of the controller and some of the drive's. This test does not write data to the disk.
ZRLH	Controller Test Part 2	Continues from above test but also tests writing to disk (so don't use an important disk pack).
ZRLI	Drive Test Part 1	Tests status and seek functionality of a drive and (optionally) loading and unloading of the heads.
ZRLJ	Drive Test Part 2	Continues from above test by testing more complicated seek operations. This test does not write to the disk (you can put it in write protect mode if you like).
ZRLN	Drive Test Part 3	Continues from above diagnostic with more seek, timing and data transfer tests, some of which involve writing to the disk.
ZRLK	Performance Exerciser	Tries to simulate a working system and tests random seeks, reads and writes on multiple drives.
ZRLL	Compatability Test	Tests that drives are compatible (i.e. they can read or write data on disks from other drives).

Quite a comprehensive list, then. All of these tests run onder the DR supervisory program of XXDP and take a good few parameters as input. I'm not sure if it's to be expected or if it's down to the particular set-up itself, but the first test took so long I ended up skipping it. The second test wasn't much quicker and, to be brutally honest, I was getting a bit tired of the whole diagnostics thing. I decided to throw caution to the wind and see if the drives seemed to work - any problems and I'd run the relevant diagnostics to see what was wrong.

Powering up the drives showed promise: no FAULT lights and after a few seconds the LOAD light came on indicating a disk pack could be inserted. This means the drives were getting the necessary signals from the controller, so everything is connected correctly. Unfortunately the first drive didn't want to take the pack, indicating a fault after spinning up - something to look into later. The second drive was much more co-operative. After inserting the pack the drive spun up nicely and the white READY lamp illuminated. I replaced the blank pack I was using as test media with an RT-11 boot disk and restarted the machine. I didn't have to do a thing as the boot ROMs quickly found the disk and automatically booted it for me.

So the PDP-11 is now running an OS without any help whatsoever! There's still plenty to do, however, such as fixing that faulty RL02 drive. Unfortunately the TU58 emulation set-up has gone all unreliable again so running diagnostics is a bit of a pain. High time, therefore, that I cut myself an XXPD boot disk on RL02...

Next: Fixing an RL02 >>